Choose a human grounding tester for the workshop
At the daily electronic production site, there is often a feedback on the static voltage of the employees in the workshop. I don't know where the problem is, how can the static electricity on the human body be removed? ANSI/ESD S20.20 stipulates that the 芏 and floor system resistance is <1-109 Ω, and the electric voltage is <100V peak when people wear anti-static shoes while standing on the floor. Anti-static wrist straps must be used by people who operate SSDs. When using wrist straps, theoretically, wrist straps should be in good contact with human wrists, grounding cables and grounding wires. Wire resistance is 0.8*106Ω; ground resistance is <3.5* when worn. 107Ω. When using the wristband, be sure to pay attention to the love grounding, to ensure that the contact resistance is small, the grounding metal core diameter of the wristband should be greater than 1.5MM2, and the elastic band must contain the conductive wire.
To do a good job of human body static protection, we must go through strict technical control. At present, the customer uses a lot of human body static detectors with access control system at the door of the workshop. The electrostatic protection is up to standard, and the gate will open the door for employees to enter the workshop. How to choose a human grounding tester suitable for workshop use?
One: What is the function of the human body grounding tester?
In the market, there are many names for the human body grounding tester, such as the human body comprehensive tester or the wrist strap/antistatic shoe tester, which actually refers to the same instrument. This type of instrument is installed at the entrance of the electrostatic protection zone (shop door).
Detecting whether the resistance of employees wearing anti-static wrist straps and work shoes is within the acceptable range, only qualified employees can enter the electrostatic protection zone (EPA).
Two: What is the difference between a human body grounding tester and a real-time grounding monitor?
The human body grounding tester is mainly installed at each door point, and the qualified employees are allowed to enter, usually combined with the access control. The real-time grounding monitor is installed on a fixed workstation to monitor the grounding of the human body, countertops and equipment in real time. for Mobile personnel cannot use real-time grounding monitors, and the moving personnel are grounded through anti-static shoes, so they can only be detected by the human grounding tester.
Three: What is the difference between the human body grounding tester and the wrist strap tester?
The wrist strap tester is to check whether the resistance of the wrist strap itself is qualified. The human body grounding tester is qualified to detect the grounding resistance of the human body through the wrist strap, so the human body grounding tester tests the human body resistance + wrist strap resistance.
Four: What are the operational precautions for the human body grounding tester?
Pay attention to the following to avoid damage to the instrument and confusion in use:
1) The tester itself must be reliably grounded: the static electricity generated by the human body may be introduced into the internal circuit board of the instrument through fingers. If the tester is not grounded or the grounding is unqualified, the internal chip may burn out.
2) Keep the test button dry without contaminants, otherwise there is a risk of short circuit
3) The resistance of anti-static shoes may change due to different weather temperature/humidity or pollution degree. Sometimes it is qualified and sometimes unqualified. This is not a tester problem, it is the resistance change of anti-static shoes.
Five: How to calibrate the human grounding tester?
After the tester is installed, it is not easy to remove it, so it is not very convenient to send the instrument to the third-party calibration. It is recommended to purchase the original standard resistance box, first calibrate the standard resistance box, and then use the qualified standard resistance box in practice. The location is calibrated to the human ground tester, which is a simple and efficient way.